The stomach, appendix, jejunum, ileum, ascending colon, transverse colon, descending colon, liver and spleen are attached to the posterior part of the abdominal wall by mesenteries which carry blood vessels and lymphatics to and from these organs. The mesenteries also contain lymph nodes. The mesenteries vary in thickness, but all contain large amounts of fatty tissue and blood vessels which vary in size from 1.0 cm. in diameter down to less than 0.1 mm. in diameter. The greater omentum is a double fold of mesentery and it too carries large numbers of blood vessels of varying size, and the thickness of the greater omentum is quite variable from one patient to another.
There are stapling devices for closing the bronchus, pulmonary artery, pulmonary veins, for closure of the large or small intestine, for closure of the stomach or stapling of the stomach for morbid obesity, for end-to-end anastomosis of the intestines, for side-to-side anastomosis of the intestines and for individual ligation and for division of a blood vessel. In addition, there is a variety of occluding clips for blood vessels and skin staplers. Because of the fatty tissue and the variety of sizes of blood vessels present in the mesentery and the omentum, the available staplers are not satisfactory for stapling the mesentery and the omentum. The best stapler only ligates one vessel at a time and it commonly tears blood vessels in the vicinity of its use, requiring time-consuming repairs after ligation of the intended vessel.
U.S. Pat. Nos. 4,606,345 (Dorband et al), 3,252,643 (Strekopytov et al), 3,795,034 (Strekopytov et al) Roehr et al U.S. Pat. No. 4,715,520 were cited against the parent applications.
The Dorband et al patent describes a stapler gun and a method for stapling two staggered rows of two-part fasteners for joining body tissue with two-part plastic fasteners which are believed to be more suitable for remaining in the patient as compared to stainless steel staples. The device is designed to provide two rows of fasteners, which fasteners may be made of biologically absorable or non-absorbable polymeric materials. One part of the fastener comprises a U-shaped staple which has legs that are caused to penetrate the tissue. The other part of the fastener is placed on the other side of the tissue and used to engage the legs of the staple and interlock therewith. There is no disclosure of three rows of fastening devices, nor is there any disclosure of variations in the size of the fasteners, nor is there any discussion of this arrangement being satisfactory for use with a patient's mesentery.
The Strekopytov patents (U.S. Pat. Nos. 3,252,643 and 3,795,034) teach an older type of device used for applying rows of staples. While both patents teach the use of a third row of staples, this third row is spaced a considerable distance from the first two rows of staples and is "adjacent the opposite side edge of the jaw" of the stapler. Therefore because of this distance the third row does not act in conjunction with the first two rows of staples but merely provides a separate single row of staples. Moreover there is no reference to any differences in sizes of the staples in any of the rows.
The Roehr et al patent shows a stapler which applies three rows of staggered staples. However the staples in each row are identical in size to the staples in the other rows. There is no reference to any variation in the size of the staples.